package main

import "fmt"

type ByteSize float64

const (
	_           = iota // 通过赋值给空白标识符来忽略值
	KB ByteSize = 1 << (10 * iota)
	MB
	GB
	TB
	PB
	EB
	ZB
	YB
)

type BitFlag int

const (
	Active  BitFlag = 1 << iota // 1 << 0 == 1
	Send                        // 1 << 1 == 2
	Receive                     // 1 << 2 == 4
)

func main() {
	flag := Active | Send // == 3
	fmt.Println("flag: ", flag)
}
